day 2 2025

1 files changed, 103 insertions, 0 deletions

diff --git a/2025/day_02_part2.cbl b/2025/day_02_part2.cbl
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+       IDENTIFICATION DIVISION.
+       PROGRAM-ID. day_02_part2.
+       AUTHOR. Trey Bastian.
+       ENVIRONMENT DIVISION.
+       INPUT-OUTPUT SECTION.
+       FILE-CONTROL.
+       SELECT input-file ASSIGN TO "./input.txt"
+           ORGANIZATION IS LINE SEQUENTIAL.
+       DATA DIVISION.
+       FILE SECTION.
+       FD input-file.
+       01 input-line PIC X(4096). 
+       WORKING-STORAGE SECTION.
+       01 ptr PIC 9(4) Value 1.
+       01 len PIC 9(4).
+       01 left-val PIC 9(32).
+       01 right-val PIC 9(32).
+       01 grouping PIC X(65).
+
+       01 val-string PIC Z(32).
+       01 val-string-len PIC 9(2).
+       01 val-string-start-idx PIC 9(2).
+       01 val-string-half PIC 9(2).
+       01 val-window PIC 9(2) VALUE 1. 
+       01 c-idx PIC 9(2).
+       01 s-left PIC Z(16).
+       01 s-right PIC Z(16).
+       01 no-match PIC X VALUE "N".
+       01 result PIC 9(32) VALUE ZEROS.
+
+       01 eof PIC X.
+           88 eof-y VALUE "Y".
+           88 eof-n VALUE "N".
+       PROCEDURE DIVISION.
+         OPEN INPUT input-file.
+         SET eof-n to TRUE.
+         PERFORM UNTIL eof-y
+             READ input-file AT END
+                 SET eof-y to TRUE
+             NOT AT END
+              INSPECT input-line TALLYING len FOR CHARACTERS BEFORE
+              SPACE
+
+              PERFORM UNTIL ptr > len
+                UNSTRING input-line DELIMITED BY "," INTO grouping WITH
+                POINTER ptr
+                END-UNSTRING
+
+                UNSTRING grouping DELIMITED BY "-" INTO left-val,
+                right-val
+                END-UNSTRING
+                
+                PERFORM VARYING  left-val FROM left-val BY 1 UNTIL
+                  left-val > right-val
+                  MOVE left-val TO val-string
+
+                  COMPUTE val-string-len = FUNCTION LENGTH(FUNCTION
+                  TRIM(val-string))
+
+                  COMPUTE val-string-start-idx = 
+                  (FUNCTION LENGTH(val-string) - val-string-len ) + 1
+
+                  COMPUTE val-string-half = val-string-len / 2
+
+                  PERFORM VARYING val-window FROM 1 BY 1 
+                    UNTIL val-window > val-string-half
+                    COMPUTE c-idx = val-string-start-idx + val-window
+                    MOVE "N" to no-match
+                    PERFORM VARYING c-idx 
+                      FROM c-idx 
+                      BY val-window
+                      UNTIL c-idx
+                      > FUNCTION LENGTH(val-string)  
+
+                      MOVE val-string(val-string-start-idx:val-window)
+                      TO s-left
+
+                      IF (c-idx + val-window 
+                        > FUNCTION LENGTH(val-string))
+                           MOVE val-string(c-idx:) TO s-right
+                       ELSE
+                           MOVE val-string(c-idx:val-window) TO s-right
+                       END-IF
+                      
+                      IF NOT s-left = s-right 
+                        MOVE "Y" to no-match
+                        EXIT PERFORM
+                      END-IF
+                    END-PERFORM
+                    IF no-match = "N"
+                      ADD left-val to result
+                      EXIT PERFORM
+                    END-IF
+                  END-PERFORM
+                END-PERFORM
+              END-PERFORM
+
+              END-READ
+         END-PERFORM.
+         CLOSE input-file.
+         DISPLAY result.
+       STOP-RUN.
+